package com.jwmp.core.util;

import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;

/*
 * MD5 算法
*/
public class MD5 {
    // 全局数组
    private final static String[] strDigits = { "0", "1", "2", "3", "4", "5",
            "6", "7", "8", "9", "a", "b", "c", "d", "e", "f" };

    public MD5() {}

    // 返回形式为数字跟字符串
    private static String byteToString(byte bByte) {
        int iRet = bByte;
        if (iRet < 0) {
            iRet += 256;
        }
        int iD1 = iRet / 16;
        int iD2 = iRet % 16;
        return strDigits[iD1] + strDigits[iD2];
    }

    // 转换字节数组为16进制字符串
    private static String byteArrayToString(byte[] bArr) {
        StringBuffer sb = new StringBuffer();
        for (int i = 0; i < bArr.length; i++) {
            sb.append(byteToString(bArr[i]));
        }

        return sb.toString();
    }

    public static String md5Hasp(String sourceData) {
        try {
            MessageDigest md = MessageDigest.getInstance("MD5");
            // md.digest() 返回值存放哈希值结果的 byte 数组
            return byteArrayToString(md.digest(sourceData.getBytes()));
        } catch (NoSuchAlgorithmException ex) {
            ex.printStackTrace();
        }
        return null;
    }

    public static void main(String[] args) {
        MD5 getMD5 = new MD5();
        // root admin： 9aef44e056a783bfea735c6509f44bc1
        System.out.println(getMD5.md5Hasp("admin" + "root".substring(1)));
    }
}